The objective of this contract is to test chemicals for mutagenicity in Salmonella. The chemicals are tested, under code, in a series of Salmonella tester strains, both with and without metabolic activation. The results of this testing are used, in combination with other information, to evaluate the toxicity, and potential carcinogenicity, of the chemicals. The results of the testing are distributed throughout the Program, to other Federal agencies, and to other public and private organizations, and are published in the peer-reviewed scientific literature.